The kobuki foundation alone doesn't drift, so it is sensible that the tilted inertia brings about the drift. Naturally I am able to hack my URDF by using a weightless superstructure, but I needed to fix this in a far more realistic way. I tried all I am able to https://www.uk-exhibitionstands.co.uk/3-trade-show-mistakes-to-avoid-and-how-to-fix-them/